the population in this battleground state, a million people either call themselves catholic or eveng el angelical. this is key especially when you're talking about a state like iowa, which folks here describe to me as split right down the middle or a purple state. in the heart of des moines, evangelical christians flock to grace church to talk faith, family and the presidential election. >> honestly, what it all boils down to is what does the bible say and which candidate is going to follow the closest? >> for bob and rachel bradshah, that candidate is mitt romney. >> i don't know how voters loik mine the president could be for abortion the way he is, and support same-sex marriage. it's hard for me to -- somebody that claims to be a christian, you know, make statements to support things like that. >> it can't be an easy choice to make either way. >> reporter: wrestling with their votes. >> my religious beliefs, if anything it's probably going to end up being mitt romney. >> 57% of voters in the republican iowa caucuses identify themselves as evangelicals, supported rick santorum over mi